The Satiating Effect of Extruded Plant Protein Compared with Native Plant and Meat Protein in a Ragú "Bolognaise" Meal: A Randomized Cross-Over Study

Protein increases satiety by, among other things, increasing the content of certain amino acids in the blood. Plant proteins generally have a lower digestibility than meat proteins. The digestibility increases after extrusion; thereby, extrusion potentially also increases the satiating effect. We investigated subjective appetite and ad libitum energy intake (adlib_EI) following ragú "bolognaise" meals with three different protein sources. We hypothesized that the satiating effect of texturized vegetable proteins (TVP) was comparable to that of animal protein (Meat) and that TVPs would have a stronger satiating effect than non-texturized legume proteins (Green). Test meals were theoretically designed to be similar in weight, energy (kJ), macronutrients and fiber. The in vitro protein digestibility (IVPD) and the amino acid composition were analyzed. A randomized, single-blinded, three-way, cross-over study including 25 healthy men was carried out. There were no significant differences between the three meals in terms of subjective appetite. The adlib_EI was significantly lower after the TVP meal (758 kJ) than after the Meat meal (957 kJ), with the Green meal in between (903 kJ). The IVPD was significantly higher in the Meat meal (30.72%) than in the Green meal (20.17%), with the TVP meal in between (21.05%). In conclusion, the TVP meal had a higher long-term satiating effect than a similar meal with meat.